Traditional methods of constructing and fabricating poured concrete walls typically involve the usage of forms made from sheets of plywood, solid wood, metal, or plastic composites, whereby the sheets are held apart a predetermined distance, generally in a parallel arrangement, by a plurality of exteriorly placed structural members to form an interior cavity or space for receiving therewithin a specified amount of pourable concrete. After allowing the poured concrete to harden for an appreciable amount of time, the form assembly is systematically disassembled to leave a bare concrete wall for supplemental curing of the concrete to attain full structural strength thereof.
Like the traditional method of concrete wall formation, Insulating Concrete Form (ICF) systems utilize a stacked arrangement of foam panels or blocks in lieu of the noted sheets of material and a plurality of panel spacing ties in lieu of the exteriorly placed structural members to form the preferential shape of the interior cavity or space for receiving therewithin a specified amount of pourable concrete. Although the two methods share similar structural features in this regard, the ICF system has been fielded test and proven to offer superior performance characteristics over the traditional method of wall construction in terms of strength, flexibility, energy efficiency, and time and cost of fabrication and, in this regard, is considered the preferred method by which poured concrete walls are fabricated in building structures with space heating and cooling needs, notwithstanding some noteworthy limitations in the prior art. However, unlike the traditional method of wall construction, the foam panels or blocks of the ICF system are generally left intact to form part of the concrete wall structure insofar to offer a degree of thermal insulating qualities thereto.
In the particular instance of ICF systems, the foam panels may be made from rigid foam insulating materials and appropriately molded, cut, or extruded to comprise a variety of structural provisions that facilitate connection of the panel spacing ties thereto and provide for an interlocking relationship with neighboring panels to fulfill a unified and strengthened form assembly, such as the existence of an alternating arrangement of teeth or projections and spaces or sockets integrated within and along the upper and lower edges of the foam panel and tongue-and-groove configurations integrally present along the opposing vertical edges, as generally represented in U.S. Pat. No. 7,409,801 to Pfeiffer. Notwithstanding recent strides in the prior art in developing ICF systems comprising features for increasing rigidity and strength, perhaps as such to guard against hydrostatic blowout from excessive concrete pours and offer flexibility for onsite assembly, as generally exemplified by U.S. Pat. No. 6,935,081 to Dunn, et al., it is often observed that the foam panel may lack other structural provisions that are necessary and integral in fulfilling a finished concrete wall structure, such as exterior and internal drainage channels and outlets for the release and passing of water or accumulated moisture, means for even distribution of poured concrete within the interior cavity to mitigate occurrences of developing a honeycomb effect that can unduly compromise the strength of the concrete wall structure, integral chaseways adaptively suited for receiving and housing electrical wiring and plumbing lines, availability of continuous vertical supports for subsequent finishing of the insulated concrete wall structure, and so forth. It is often the case that these structural oversights within the foam panel are generally addressed at a later time during the construction phase of the building structure and completed by personnel other than by those responsible for erecting the ICF system and, consequently, can significantly add to the final cost of the finished concrete wall structure in terms of time to adequately accommodate the foregoing features at a moment of time well beyond placement of the ICF system.
Comparatively, the panel spacing ties may comprise one or more structural provisions that fulfill opportunities to lessen the effective volume of the ICF system for shipping purposes as well as to facilitate efficient onsite assembly of the foam panels or blocks constituting the ICF system. Commonly, in applications of onsite form assembly, the foam panels and panel spacing ties are shipped to the job site unassembled to maximize usage of the available shipping space in prospects of reducing costs as a tradeoff for erecting the concrete wall form assembly under the auspices of experienced onsite field personnel. In this instance, the panel forms are stackably arranged onsite in a manner conducive to forming a parallel wall structure with an interior cavity and appropriately held in this arrangement by means of fitting a number of flange members integral to the panel spacing ties within a series of formed grooves integral to the foam panels, paying particular attention not to unduly disrupt the integrity and alignment of the foam panels during installation of the panel spacing ties.
In an effort to reduce costly errors that may be inherently associated with the onsite assembly of the foam panels shipped apart from the panel spacing ties, there has been development in the art to pre-fit the panel spacing ties in full or in part within the foam panels during manufacture thereof in an attempt to offer a degree of compactness for economical shipping and, in some cases, simplify assembly by onsite field personnel.
One example of this approach is disclosed in U.S. Pat. No. 7,082,732 to Titishov, where the ICF system includes a panel spacing tie being fabricated as three separable components: a central web section held in between two end sections. The two end sections are described within the context of Titishov as being embedded in first and second foam panels during the manufacturing phase, while the central web section is hinged to the end sections by pins that permits the opposing foam panels to move inward toward one another in an offsetting, parallel manner to attain compactness for economical shipping and moved apart from one another in an expanded state during onsite assembly of the ICF system to form an interior cavity constituting the shape of the concrete wall structure.
Similar to Titishov in terms of attaining compactness of the ICF system for economical shipping, U.S. Pat. No. 6,915,613 to Wostal, et al. discloses an ICF system comprising in part a plurality of articulating spacers each composed of a pair of spacer links having elbow ends pivotally joined midway along the articulating spacer and opposite wall ends connected to protruding web portions of a web configured with anchoring plates embedded within the structure of the opposing foam panels. Pivotal movement of the spacer links about the elbow ends effectively collapses the articulating spacer in such a manner to form a parallel relationship of the spacer links while moving inward the connected, opposing foam panels to fulfill compactness of the ICF system. Conversely, movement of the spacer links apart from one another while being in a collapsible state beforehand establishes a linear relationship of the spacer links to the extent of openly expanding the foam panels to form an interior cavity for receiving therewithin pourable concrete constituting formation of the wall structure.
Although Titishov and Wostal each disclose a novel approach to fulfill compactness of the ICF system for economical shipping thereof and offer a modest degree of simplicity for onsite assembly of the ICF system, there are inherent disadvantages associated with each approach, most notably being attributed to the multitude of intricate components constituting the panel spacing tie that perhaps can subject it to failure in the backdrop of high manufacturing costs.
For example, the panel spacing ties in either Titishov or Wostal depend on the coordinated movement of a variety of sub-components that slidably engage with one another to facilitate compactness or expansion of the ICF system. It is conceivable within the context of their designs that an appreciable amount debris and other foreign matter could find its way within the intricate structure of the sub-components during onsite assembly of the ICF system that can unduly compromise the range of motion or sliding movement needed to effect complete and accurate assembly of the ICF system and, in instances of sizeable debris or amounts thereof interacting with the sub-components in particular, can render them completely inoperable or subject them to breakage. Furthermore, since structural portions of the panel spacing tie, such as the flange components thereof, permanently reside or are formed within the matrix of the foam panel during the manufacturing phase, any breakage of the sort mentioned above may require extensive repair or render the foam block assembly entirely useless, thus unnecessarily adding to the overall time and cost in completing the finished wall structure.
Accordingly, there remains a need for an ICF system that utilizes a plurality of foam panels or blocks incorporating structural attributes that appreciably advances the concrete wall structure toward completion without having to resort to further modification or alteration of the foam blocks at a moment of time well beyond the assembly of the ICF system, while offering a plurality of panel spacing ties that operably relies on a reduced number of moving sub-components to fulfill compactness of the ICF system for purposes of economical shipping and flexibility for either onsite and offsite assembly as additional cost saving measures for completing and finishing the concrete wall structure.